Liquid Holdup in Catalyst‐Containing Pockets of a Modular Catalytic Structured Packing

This paper introduces a simple, first principles‐based model describing the liquid holdup in the catalyst‐containing pockets of Katapak‐SP, a modular catalytic structured packing developed to allow a certain degree of flexibility with respect to the variation in reaction‐to‐separation requirements in a single unit. The basic requirement for the catalyst‐containing pockets in this respect is to be fully filled with flowing liquid which implies that the operating holdup is bound between the static holdup of the catalyst bed as the lower end, and that corresponding to the upper limit, the so‐called catalytic load point. The latter is the liquid load corresponding to the bed saturation point, indicating that excessive liquid will be retained, i.e., will remain in the separation part of the packing element and mix with the liquid leaving the catalyst‐filled pockets at the bottom of the element. Detailed knowledge of the liquid holdup as well as the pattern of the trickling flow is essential because it governs the performance of the reaction part and consequently the hybrid unit as a whole. Both glass and resin (an industrial catalyst) particles were used in conjunction with water and a binary water‐methanol mixture as working fluids. The model predictions for static holdup and the catalytic load agree well with the experiments.     

Chitosan and marine phospholipids reduce matrix metalloproteinase activity in myeloma SP2 tumor‐bearing mice

An animal experiment was conducted to assess the antitumor effects of chitosan‐coated liposomes on myeloma SP2. The animal experimental groups designed for myeloma SP2 tumor‐bearing BALB/c mice were provided with five different drinks: (I) control (double‐distilled water); (II) squid phospholipid liposomes alone 1.0 mg/mL; (III) chitosan alone 5.0 mg/mL; (IV) squid phospholipid liposomes 1.0 mg/mL with chitosan 5.0 mg/mL in the form of a simple mixture; and (V) squid phospholipid liposomes 1.0 mg/mL coated with chitosan 5.0 mg/mL. At 20 days after implantation of the myeloma SP2 cells into mice, oral administration of the experimental drinks was provided for 35 days. There was significant suppression of tumor growth when chitosan and squid phospholipids were administered simultaneously in a simple mixture or as chitosan‐coated liposomes. Matrix metalloproteinase (MMP)‐2 and MMP‐9 activity was significantly less in the serum of mice that consumed chitosan‐coated liposomes than in control mice. We found that decreased tumor burden was related to MMP secretion. Therefore, chitosan‐coated marine phospholipid liposomes might be useful as potential agents for the treatment of myeloma SP2.     

IMS业务能力开放模式及应用探讨

开放电信业务能力,实现电信与互联网业务的聚合已经是业界的共识,IMS体系的业务能力引擎标准化对实现业务能力开放有着极大的优势。文章通过对互联网引入电信业务能力的需求进行分析,指出IMS业务能力开放的关键需求,并结合IMS的架构特点,提出IMS业务能力开放的主要模式及应用建议。     

浅析移动增值业务的发展趋势

近年来移动增值业务以强劲的增长速度、快速的市场渗透力创造了巨大的经济效益。在我国,移动增值业务为运营商带来了显著的经济效益,成为拉动总业务收入的生力军。与此同时,一个基于移动通信的信息服务产业应运而生,形成了以基础电信运营商、服务提供商（SP）、内容提供商（CP）和各类应用开发商等共同组成的新兴产业。随着信息通信技术和互联网的快速发展,人们对移动增值业务的需求也逐步呈现综合化、多媒体化和个性化的发展趋势。在当前背景下,各种网络新技术的研究和应用的根本目的都是提升服务和业务能力,其关键就是实现业务的融合与统一。     

H.264/AVC中SP帧技术的应用研究

SP帧技术是H.264/AVC新视频标准中定义的新类型帧技术。其主要特点是:即使使用不同的参考帧也能预测恢复出相同的SP帧,因而SP帧可以在流间切换、拼接、随机插入以及差错控制等应用中取代I帧实现相应功能。文章在介绍基于SP帧技术各种具体应用的基础上,通过大量仿真试验对SP帧进行了各种情况下的研究,并从中获得具有指导性的结论。     

利用自然电位计算泥质砂岩地层水电阻率的方法

地层水电阻率是测井解释中一个极其重要的参数,以纯地层条件推导的用于确定地层水电阻率的自然电位理论模型不适合泥质砂岩地层。针对含油气泥质砂岩储层,提供了改进的自然电位模型,它考虑到阳离子交换容量、含油气饱和度的影响,提供改进的自然电位模型可以有效地用于确定泥质砂岩地层的地层水电阻率。     

基于Freescale单片机的电子控制空气悬架模糊PID控制

以 Freescale 公司的 MC9S08GB60A 单片机为控制芯片,以 YBL6891H 型客车的1/4车辆模型为研究对象,设计了一种客车用空气悬架的电子控制单元。该控制单元以车身垂直加速度的均方根为主要控制目标,采用了模糊 PID 控制算法,并用 MATLAB/SIMULINK 对该模型进行了仿真,仿真结果表明,利用该控制系统能很好地抑制客车的振动。     

浅析H08A气泡缺陷的质量控制

针对新钢公司炼钢厂方坯连铸机在生产H08A连铸坯时容易产生气泡缺陷现象进行了原因分析,提出了改进措施与检验方法,取得了一定的效果.     

The relationship between sensitisation and small punch test behaviour in a high-nitrogen austenitic stainless steel at cryogenic temperatures

Austenitic stainless components used in nuclear fusion reactors must be capable of maintaining reasonable mechanical properties to thermal ageing caused by welding and in‐service. Recently, high‐nitrogen (High‐N) austenitic stainless steels (SS) are receiving increased attention because of their strength advantages, but they have been found to be susceptible to dichromium nitride (Cr₂N) precipitation during thermal exposure at 823–1073 K. The susceptibility to sensitisation at thermal ageing temperature for high‐N austenitic SS is examined using the single‐loop electrochemical potentiokinetic reactivation (EPR) test. High‐N SS were found to be susceptible to sensitisation caused by grain boundary precipitation of Cr₂N, with the degree of sensitisation increasing systematically with ageing time and temperature. In particular, it was found that the precipitates, which effected sensitisation, were changed from carbides (M₂₃C₆) to nitrides (Cr₂N) with increasing ageing time and temperature. The deterioration of mechanical properties associated with thermal ageing in high‐N SS was investigated by a small punch (SP) test using miniature specimens at cryogenic temperatures. Results indicated that the degradation of mechanical properties in this alloy was caused by a decrease of cohesive strength resulting from carbides (Cr₂₃C₆) and nitrides (Cr₂N) precipitated in grain boundaries.     

一种确定水淹层地层水电阻率的方法

论述了砂泥岩剖面的储集层淡水水淹的机理及其在自然电位测井曲线上的显示特征,以及如何应用自然电位测井曲线判断水淹,计算水淹层地层水电阻率。